Which example requires the use of a one to many, parent child custom object application?

Which example requires the use of a one to many, parent child custom object application?

A.
Your customer wants to keep track of the end customer’s Customer identification Number

B.
Your customer has stated that they want to report on end customers that have similar attributes.

C.
Your customer has stated that they want to track when end customers are contacted by sales
associates.

D.
Your customer wants to keep track of all the cars the end customers drive.

Explanation:

One single customer may use many cars.